It is well known that there are concrete trucks for depositing concrete at a job site, for example, into a foundation ditch. Generally, there are two types of such trucks:                a) a first type of truck, which includes a rotatable, generally cone shaped, downwardly tilted turning drum in which a charge of cement, sand, rocks and water, and, sometimes, short lengths of reinforcing fiber lengths, are mixed in the turning drum while in transit to a job site and to be dispensed at the job site from the drum as a flowable mix onto one end of a chute extending from the truck; and        b) a second type of truck, to which this invention is relevant, which is used to transport and dispense separate concrete ingredients in separate compartments which are carried to the job site by the truck; however, the ingredients are mixed at the job site, rather than in transit to the job site, and, then, they are dispensed from the truck.        
With the second type of truck there has been a problem of adding short fiber reinforcing lengths to the combined output from the truck flow of separate concrete ingredient flows, so that, in the combined out flow from the truck, the short fibers lengths are not clumped or grouped, but, rather, are randomly dispersed generally in a quite uniform reinforced concrete mix. Past efforts to introduce chopped short fiber lengths into a flow of concrete ingredients have resulted in clumping or grouping of the fibers; and, as a consequence, the tensile strength enhancement sought of the concrete mix, when set, is not achieved. Past efforts have included hand dispensing of packaged pre-chopped short fiber lengths by dropping short lengths of chopped fiber directly onto an out flow of the concrete ingredients from the truck.
Although not described as being for a chopper for use on a truck, U.S. Pat. No. 5,316,197 describes an apparatus for depositing short fiber lengths onto a conveyor system; and this patent sets forth in some detail the past prior art problem, namely that of of clumping and grouping which this invention specifically addresses. In short, this invention is of an apparatus and of a process for developing a uniform concrete mix of concrete ingredients, water and short cut lengths of fiber strand at a job site and selectively depositing the mix on a delivery truck of the second type described above.
A general object of this invention is, therefore, to provide an apparatus and process which overcomes the past fiber strand grouping and clumping problem involved in delivering separate fiber strand reinforced concrete ingredients to a job site, mixing the ingredients at the site and depositing them to set up as fiber reinforced concrete in a structure being erected.